What’s Vulnerable › Vulnerabilities

CVE-2026-23621: GFI MailEssentials AI < 22.4 ListServer.IsPathExist() Absolute Directory Traversal to File Enumeration

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-02-19 · updated 2026-06-17
• Weakness: CWE-203

Description

GFI MailEssentials AI versions prior to 22.4 contain an arbitrary directory existence enumeration vulnerability in the ListServer.IsPathExist() web method exposed at /MailEssentials/pages/MailSecurity/ListServer.aspx/IsPathExist. An authenticated user can supply an unrestricted filesystem path via the JSON key \"path\", which is URL-decoded and passed to Directory.Exists(), allowing the attacker to determine whether arbitrary directories exist on the server.

Affected products

• GFI Software MailEssentials AI: before 22.4 — fixed in 22.4

How to fix

Upgrade to a fixed version: GFI Software MailEssentials AI 22.4. Check the vendor advisory for mitigations.

References

• https://gfi.ai/products-and-solutions/network-security-solutions/mailessentials/resources/documentation/product-releases
• https://www.vulncheck.com/advisories/gfi-mailessentials-ai-listserver-ispathexist-absolute-directory-traversal-to-file-enumeration

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